package org.apache.lucene.analysis;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.io.IOException;

/**
 * Removes words that are too long and too short from the stream.
 * 
 * 
 * @version $Id: LengthFilter.java 564715 2007-08-10 18:34:33Z mikemccand $
 */
public final class LengthFilter extends TokenFilter {

	final int min;
	final int max;

	/**
	 * Build a filter that removes words that are too long or too short from the
	 * text.
	 */
	public LengthFilter(TokenStream in, int min, int max) {
		super(in);
		this.min = min;
		this.max = max;
	}

	/**
	 * Returns the next input Token whose termText() is the right len
	 */
	public final Token next(Token result) throws IOException {
		// return the first non-stop word found
		for (Token token = input.next(result); token != null; token = input
				.next(result)) {
			int len = token.termLength();
			if (len >= min && len <= max) {
				return token;
			}
			// note: else we ignore it but should we index each part of it?
		}
		// reached EOS -- return null
		return null;
	}
}
